Possessed boss ritual

How is the challenge "Defeat a Unique Map Boss that is Possessed while in a Ritual" not triggered by this.

Both bosses were possessed, 3rd ritual of 4, I win.
Challenge not counted

Bug 3,328,755,890, image at the link https://imgur.com/a/3BshHrO

https://imgur.com/a/3BshHrO

ty

Tried many different methods and have seen others mention similar issues with credit for this challenge. After reading the above - tested again twice with two maps which both had Haunted Rituals.

Last map was Chateau where I was able to drag Argus into a ritual circle. Prior to killing him, triggered ritual and waited until he was possessed. Killing did not provide credit.

Considerations for code issues (or lack of clarity in challenge semantics):
- boss was not "spawned in" traditionally via arena-load on this map. Likewise, testing on the second map (non-arena) failed to reward challenge.
- limited sources of "possession" (map mod with "boss possessed" + % chance spirits escape via scarab did not count toward challenge). Note that this instance qualified under BOTH pre-ritual possession, and post-ritual possession.
- boss was not "resurrected" by the ritual mechanic (tested by bringing boss into ritual ring without killing, starting haunted ritual, and awaiting possession prior to killing) did not reward challenge.